UUID Generator
Random UUID v4, time-ordered v7, name-based v5, ULIDs and NanoIDs, up to 1,000 at once. Paste any UUID to see its version and the time inside it.
Showing the first 200. Copy all or download to get every one.
122 random bits from crypto.getRandomValues. The safe default when you just need a unique ID.
Starts with the current time in milliseconds, so new IDs sort after old ones and database indexes stay fast. IDs in one batch keep their order.
The same namespace and name always give the same UUID, so you can rebuild an ID without storing it. Not secret: anyone with the name can work it out.
Time first, then 80 random bits, in Crockford Base32 (no I, L, O or U). Sorts by creation time, even as text.
random bits. You could make about of these before there is a 1% chance two match.
Spaces and case count: “Example” and “example” give different UUIDs.
Inspect a UUID or ULID
Check that an ID is valid, see its version, and read the creation time out of v1, v6, v7 and ULID values.
- Valid
- Version
- Variant
- Standard form
- Node (often the MAC address)
Which one should I use?
- Database primary keys: UUID v7 (or ULID). Inserts stay in index order.
- IDs that must not reveal when they were made: UUID v4.
- The same ID for the same thing, every time: UUID v5.
- Short IDs in URLs: NanoID.
Need a secret, not an ID?
IDs are meant to be shared. For API keys and session tokens, use the Random String Generator; for logins, the Password Generator.
About the UUID Generator
A UUID is a 128-bit identifier, written as 36 characters like 550e8400-e29b-41d4-a716-446655440000, that is unique without any central registry. This generator makes UUID v4, v7 and v5 (RFC 9562), ULIDs and NanoIDs with your browser’s secure random number generator, and reads the version and creation time out of any UUID you paste.
How to use it
- 1 Pick the ID type: v4 for random IDs, v7 or ULID for database keys, v5 for an ID made from a name.
- 2 Choose how many and the format: uppercase, hyphens, braces, or a JSON or SQL list.
- 3 Copy one or all of them, or download the list.
Frequently asked questions
Can two UUIDs ever be the same?
In practice, no. A UUID v4 has 122 random bits; you would need to make about 2.7 quintillion of them for a 50% chance of a single duplicate.
What is the difference between UUID v4 and v7?
v4 is fully random. v7 starts with the time in milliseconds, so new IDs sort after older ones. That keeps database indexes compact and inserts fast, which is why v7 is now the recommended choice for primary keys.
When should I use UUID v5?
When the same input should always give the same ID, for example to turn URLs or email addresses into stable keys without a lookup table. v5 hashes a namespace UUID and a name with SHA-1. It is not random and not secret.
What is a ULID?
A ULID is a 26-character ID with a 48-bit timestamp and 80 random bits, written in Crockford Base32 so it has no I, L, O or U. Like UUID v7 it sorts by creation time, and it is shorter to write.
Is a NanoID as unique as a UUID?
The default 21-character NanoID has 126 random bits, slightly more than UUID v4’s 122, in a shorter URL-safe string. Shorter NanoIDs or smaller alphabets have fewer bits; the tool shows how many you could make before a 1% chance of a duplicate.
Can I read the date from a UUID?
Yes for versions 1, 6 and 7 and for ULIDs, which store the time they were made. Paste one into the inspector. UUID v4 and v5 contain no time.
Are the IDs generated securely?
Yes. They come from crypto.getRandomValues on your device, without modulo bias, and are never sent to our server. Still, use a random token, not a UUID, for secrets such as API keys.